We are deep into seed season here on our five acres of green (now mostly brown) chaos. Strong north winds from a recent cold front made that abundantly clear, depositing an array of leaves and seeds on our front deck (and our back deck, and everywhere else for that matter).
See all the tiny bits all over the deck? I learned today that they are aborted seeds of native sweet gum trees (Liquidambar styraciflua). And thank goodness, I thought. If sweet gums produced fertile seeds that abundantly, here in the Piedmont region of North Carolina we would all be living amid sweet gum forests, likely to the exclusion of most other species.
In the photo above, I think I can see two or three fertile sweet gum seeds. Like many of our other native tree seeds, sweet gum seeds have “wings” that allow them to float far from mother trees on autumn breezes. I’m fairly certain that one fertile sweet gum seed in the picture is lying just above the pine needle bundle. Two others may or may not be in the upper right corner of the shot. It’s too fuzzy for me to be certain. A maple seed lies toward the bottom of the photo, and a seed from a tulip poplar lies above and to the right of the pine needle bundle. A discarded reddened sweet gum leaf lies among its tree’s progeny.
Sweet gums are noted for their abundance in the southeastern US. They are considered to be an early colonizer of abandoned fields and other open areas, joining loblolly pines as one of the tree species that overtops the grasses and wildflowers that first overtake open land. That process is called old field succession.
In my yard, autumn color of sweet gum leaves ranges from deep maroon to scarlet to shades of orange-yellow. I love the red ones. Folks new to the area who don’t know trees often confuse these leaves with those of maple trees, especially red maples. To my eye, they look nothing alike. To teach novices how to tell the difference, my advice is always the same: use your nose. Crunch up a leaf in your hand and inhale. If your nose fills with a refreshing spicy scent, you’re holding a sweet gum leaf. Maple leaves give off no such fragrance when crushed.
Sweet gum’s genus name, Liquidambar, translates roughly as liquid or fluid amber, referring to the fragrant juice or gum that exudes from this tree. Its species name, styraciflua, translates to “flowing with storax,” storax being an old term for plant resin.
The earliest published record of this species was written by a Spanish naturalist, who observed it growing in the New World. The tree’s range includes Mexico and parts of Central America, and the tree was utilized by Aztec tribes. Its Nahuatl name is Ocotzocuahuitl, which translates to tree (cuahuitl) that gives pine (ocotl) resin (tzotl). I would agree with these Native Americans that sweet gum resin does smell similar to that of pine trees. Another Spaniard described receiving as gifts hollow reeds filled with dried herbs (probably tobacco) and sweet-smelling liquid amber from Maya tribesmen. When lighted as demonstrated by these Native Americans, the reeds were reported to emit a pleasant scent.
Sweet gum wood has many commercial uses. It is a source of plywood, flooring, and crates, for example. And the light-colored wood is favored by certain Asian markets that use it to make chopsticks.
Sweet gum fruits are the spiky balls that hang from branches in great abundance. At some point every autumn after the balls have ripened and turned brown and hard, tiny compartments inside them release thousands upon thousands of seeds, mostly infertile. On windless late autumn days, I often hear the seeds falling softly onto dry leaves on the ground, sounding like a gentle rain. A source I read notes that goldfinches, purple finches, and squirrels eat the seeds, which I’ve seen. But I’ve also watched migrating flocks of red-winged blackbirds swarm sweet gum trees to pry seeds from dangling balls.
I know that many homeowners despise those spiky sweet gum balls, often complaining that they clutter green lawns and damage unwary bare feet when walked on. I think the easy fix for these issues is to respect the species instead of arguing with it. Non-native lawns do not contribute to the environmental health of our struggling planet. Replace the lawn you’re trying to grow beneath sweet gums and other trees with what is supposed to be there — leaves and other organic matter — the materials you find when walking through a forest. As for unwary feet, I’ll admit that walking across a big deposit of sweet gum balls can be tricky. But they don’t stay hard and spiky forever. In my yard, they have usually softened by early summer, eventually breaking down into the soil.
Over a dozen canopy-sized sweet gums grace parts of our five acres. When the spiky balls drop in early spring, I try to avoid walking on them. When I must traverse a gum-ball-carpeted area, I use a walking stick to help me maintain my balance. It’s a simple compromise that I’m happy to make in exchange for this great source of food for native wildlife, prolonged spectacular fall color for human appreciation, and a quick inhalation of spicy leaf juice during the growing season when I grab and crush one as I traverse the landscape.